An artefact in lactate dehydrogenase isoenzyme patterns, assayed by fluorescence, occurring in the serum of patients with end-stage renal disease requiring maintenance haemodialysis

Visible auto-fluorescence in biological fluids as biomarker of pathological processes and new monitoring tool

“…It must be taken into account, however, not only the complexity of emission/excitation bands but,¯rst of all, the RS e®ect. 1,5 RS or the shift of emission maximum into the long wavelength direction by lowering of excitation energy is especially pronounced at exc > 350 nm and makes the unambiguous determination of excmax = emmax impossible in principle (see serum°uorescence spectra in Ref. 1 and the set of excitation spectra in Fig.…”

“…[1][2][3][4][5][6] The main parameters were given in Refs. 2 and 3 as excmax = emmax % 320=420 nm but they need speci¯c recti¯cation because of dependence of emission on the excitation energy (\red shift (RS) phenomenon").…”

“…2 and 3 as excmax = emmax % 320=420 nm but they need speci¯c recti¯cation because of dependence of emission on the excitation energy (\red shift (RS) phenomenon"). 1,5 This visible°uorescence (VF) is not directly connected with UV°uorescent proteins and can be observed in protein-free fractions of bio°uids. 6 Moreover, the VF substance (VFS) is ninhydrinnegative.…”

“…3 The intensity of VF in serum is a reliable indicator of chronic kidneys diseases (CKD) being higher in Pts compared with healthy controls (HCs). [1][2][3][4]7,8 There are also other manifestations of possible pathological origin of VF as it can be concluded from experiments with arti¯cial brain necrosis in rats. 9 We have found a correlation between the normalized VF intensity in HDs This is an Open Access article published by World Scienti¯c Publishing Company.…”

“…10 Many e®orts have been undertaken to identify the VFS but to our best knowledge without clinically conclusive result. [1][2][3][4]7,8,11 Since VFS is present not only in CKD Pts' bodies but in those of HC too, [1][2][3][4][5][6][7] the knowledge of its nature and the role it plays in body seems to be a challenge not only for CKD Pts care but for metabolomics as a whole. Earlier we have successfully applied as an investigation method carbon nanoparticles (CNP) approach and found a plenty (> 10) of strong similarities in optical absorption,°uorescence and reactivity properties of VFS in bio°uids and CNP aqueous solutions.…”